A focusing control device includes: a sensor that has a focus detection area in which a plurality of first signal detection sections which receives one of a pair of luminous fluxes passing through different portions arranged in one direction of a pupil region of an imaging optical system including a focus lens and detects signals and a plurality of second signal detection sections which receives other one of the pair of luminous fluxes and detects signals are formed; and a processor, configured to obtain correlation values, obtain an accumulative value of the correlation values included in each of a plurality of division areas obtained by dividing a graph of the correlation values in which shift amounts are represented on a first axis in a direction of the first axis, and perform focusing control by controlling the focus lens based on the accumulative value obtained.